Mapping sediment acoustic impedance using remote sensing acoustic techniques in a shallow-water carbonate environment

Real-time trackline plots of surficial sediment acoustic impedance delineate several sedimentary facies off Garden Key in the Dry Tortugas. The sea floor within a 6 x 6 km surveyed area consists of carbonate muds (silts), sands and shell, rock, and live corals. The 4-kHz acoustic data supports this finding by providing a pictographic representation of the distribution and structure of several sediment facies types. Plotting the gridded acoustic data with commercial mapping software (Surfer) provides a three-dimensional (3D) perspective of the bottom topography with a color contour map of surficial sediment impedance (upper 0.4 m) draped over the 3D surface.